<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
    <script src="./js/jquery.min.js"></script>
    
    <div>我还在!!</div>
    <span>11</span>

    <!-- dom加载完以后再执行 -->
    <script>
       
        // jQuery对象
        $('div').hide();
        $('span').hide();
        //原生js
        var myDiv = document.getElementsByTagName('div');
        var mySpan = document.getElementsByTagName('span');
        //DOM和jQuery相互转换
        // 1、DOM转换为jQuery直接用$()包裹就行
        // 2、jQuery转DOM 用get(index)或者直接在后面加[index]
        $(myDiv).hide();
        $(myDiv)[index].display = false;
    </script>
</body>
</html>